Governing mechanism for steam turbines



W. B. FLANDERS GOVERING MECHANISM FOR4 STEAM TURBINES March 22, 1927.USZZJO() Original Filed` June 9; y1920 NVE TOR.

W.B.F om am:

Patented Mar. 22, 1927 nutren sraras Partnr ortica.

WARREN B. ELAN F PHILADELPHIA, PENNSYLVANIA, .SSIGNOB T0 WESTING- HOUSEELECTRIC AND `ll/IANFA('J'IEUItING COMPANY, A CORPORATION 0F PENN-SYLVANIA.

GOVERNING MECHANISM FOR STEAM TUB/EINES.

Application filed .Tune 9, 1920,'Seria1 No. 387,538. Renewed January 9,1926.

My invention relates to improvements in governing mechanism for steamturbines, and more particularly to that class of governing mechanismemployed to automatically shut ott the steam supply tothe turbine when apredetermined overspeed is reached.

The object of my invent-ion is the provision ot manually controlledmeans where* by the governor mechanism may be made to operate at a speedbelow that for which it is adjusted. so that the condition oi operationof the mechanism may be readily determined, and is especially intendedfor the purpose of testing the mechanism at any desired time.

I attain these objects by the mechanism. illustrated in the accompanyingdrawing, in

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which Fig. 1 is a sectional view through av turbine shaft and housingshowing details of a governing mechanism with my unprovement appliedthereto; Fig. 2 is a detail' view showing parts oi' my improvement in adiderent operative position; and Fig. 3 is a sectional view showing theiiuid bath for my improved governor.

The overspeed governing mechanism, hereafter referred to as the autostopgovernor, is mounted on a turbine-driven shaft 10. The end ot theturbine-driven shaft 10 is 30 provided with an extension 11 having adiametral recess 12. The recess 12 has two shoulders 13 and 14 and isthreaded at`15 to receive the retainer 16. which is provided with aguide opening in which the weight r 17 may slide- The retainer 16 holdsthe spring 18 in place. and due to the threaded connect-ion thereof tothe recess` the tension ot the spring 18 maybe readily adjusted. Thespring 18 also bears against piston 19 of the weightor trip element 17to maintain the piston in contactwith shoulder 14. The collar 2O tightlylits in the recess 12 lagainst the shoulder 13 and overhangs the latterin r order to limit the travel ot the piston 19. o The weight or tripelement 17 is thereby prevented from passing beyond the point necessaryto trip the lever 21 which acts througha suitable mechanism to shut offthe steam supply to the turbine. The weight 17 has its center otgravity, indicated. for example, at 17', arranged to one side of theaxis of rotation of the sha-ft 10 so that it is responsive tocentrifugal torce to move out and trip the element 21. A

A clearance space 22 is provided below the piston 19 which communicateswith the eX- terior of the turbine'driven shaft through the eccentricpassage 23. A similar eccentric passage 24 is provided on the oppositeside of the shaft l() which communicates with the passage 23 through thepassage 25. rlhe axial passage 26 communicates between the exterior ofthe shaft 10 and the passage 25 and is chamtered at its entrance asshown. In the casing 30, adjacent to the end of the turbine shaft 10, ismounted a mechanism' whereby the ends of the passages 23 and 24 may beclosed. This mechanism consists of a rod 31 provided at one end with athreaded extension of diminished diameter 32 and at the other end with aflange 33. The rod 31 is supported with reference to the casing by meansof the two bushings 34 and 35. In the space 36 between bushings 34 and35 and on rod 31 is mounted a spring 37 rest ing against bushing 34 andpressing againstV collar 38 of rod 31. Mounted on the end of rod 31 isan annular member 39 flexibly connected to the flange 33 by means of thediaphragm 40. The diaphragm 40 is secured to the annular member 39 by aseries of screws 41 and to the flange 33 by a washer 42 and rivet orother means 43. The annular member 39 is provided with one or l moreentrance passages 44 which permit oil to enter the space between theinside of the annular member 39'and the diaphragm 40.

The spring 37 pressing against collar 38 ot rod 31 serves to keep theannular member 39 inl contact with the end of the shatt 1() therebyclosing'the ends ot the passages v23 and 24. In this position theannular member 39 is prevented from rotating with -the shaft 10 by meansof the pin 45 mounted in rod 31 and engaging two slots 46 cut inopposite sides ot' the bushing 34. On the extension 32 of rod 31 may bemounted a until pin -15 clears thc face ot' bushing 3-l and then turnrod 3l until pin 45 can rest against the solid face oi bushing 534e.

The main governor ot a steam turbine. may not al ays function properlyTand in such a case it is desirable to provide n automatic stop governorto shut oil the steam supply to the turbine when too hi gli a spec-l isreached` An auto-stop governor Yfrenerally designed to become effectiveat about 10% overspeed. It the turbine has been running at constantspeed for a long time and the auto-stop governor has not been calledupon to operate, it is not uncommon :tor the auto-stop governor to eetstuck which of course renders it practically useless. This might causeserious damage to the turbine on account of overspeeding.

In order to determine the Working' conditions of the auto-stop governor.the testing' mechanism has been devised as herein' dcscribed. rllhismechanism will function only when the end ot the turbine shaft is run inoil. `When the annular member is in the disengaged posit-ion, oil Willenter par.- sage and Will have a tree path through passage 25 and outthrough passages 28 and Q4. In order to test the auto-stop lgovernor itis simply necessary to turn handle l? until pin 45 registers with slots4G. rllhe spring 3l' Will then `torce the annular member Si) against theend of the turbine shaft l0 thereby closing passages 23 and Q4 @ilentering through passage 26 Will then till passages 23,724. 25 and theclearance space belenv piston 19. Due to the centrifugal force caused bv the rotation of the turbine shaft` pressure will be built up in thecolumn of oil in passage 25 which vvill be transmitted through the oilto the clearance space 22. his pressure acting' against piston 19together with the centrifugal torce acting);

on Weight 17 will be sutiicient to cause the Weight 17 to move out andtrip the element 2l thereby7 shutting' ott the steam supplv to theturbine. If the oil pressure does not cause the mechanism to operate itWill mean that the governing` mechanism is not in the proper Working'condition. and the cause ot the trouble must be investigated.

Ililhile I have shoivn my invent-ion in but one form, it will be obviousto those skilled in the art that it is not so limited, but issusceptible ot various vother changes and modilications, Withoutdeparting; trom the spirit thereof. and I desire. therefore, that onlysuch limitations shall be placed thereupon as are imposed by the priorart or are speciiically set forth in the appended claims.

What I claim is l. In an auto-stop governing; mechanisrm the combinationof an eccentrically Weighted tripping' member, means :tor resisting'movement of the tripping member in response to centrifugal force, meansfor developing;` ccntritug'al force of Huid for application to thetripping member in opposition to said resisting means, controlling meanslor rendering the centrifugal fluid n'cssure developing means eii'ectiveor ineffective` and means ttor maintaining the latter means .nornnilhvin inetfect-ive `position.

2. rl`hc combination with an auto-stop lgovernor having an eccentricallyWeighted tripping' meniber and a spring' tor resisting movement ot thelatter in rcsponfe lo centrifugal torce, of means i'or developingceutrifugal torce ot' tluid pressure tor application to the tripping'member in opposition to the spring, controlling` means ttor renderingthe centrifugal Huid pressure developing means eltective or ineiective,and a spring for maintaining the latter means in ineiiective position.

3, An auto-stop governor'comprising a rotaryY element having; adiametral recess and axial and eccentric nassageu'avs in communicationtherewith, an eccentrically Weighted trip element Within said recess andhaving` a piston 'connected thereto, adjustable tensioning' means tosecure operation ol Vthe trip element at a predetermined speed,`

an annular member adapted to close the eccentric passage, and meanscooperating with the annular member to maintain it either in operativeor inoperative position 4. An auto-stop governor comprising a rotaryelement adapted to be immersed in a liquid, an eccentricalli Weightedtrip elenent carried therein7 and capable ot movingv to tripping'position on attaining` a predetermined speed, va piston secured to saidtrip element7 said rotary element having' axial and eccentric passagescommunicating with the space beneath the piston, a ring element adaptedto close the Veccentric passages and havingl ports to ati'ordcommunication or" the axial passage With the exterior When the ring isin close-d position, a flexible diaphragm connected to the ringiandmanually controlled means connected to the diaphragm for moving' thering into and out ot position.

5. In a governor mechanism the combination of a rotary element having' arecess With apiston chamber at the lower end, an eccentrically Weightedelement Within the recess and having` a piston fitting Within the pistonchamber, spring` means associated With said element to secure movementthereot to tripping' position upon attainment ot a predetermined speedby the rotar)7 element, said rotar)7 element having` axial and eccentricpassap'es in comnmunication With the undersurtace ot' the pi `ton andmeans to close the eccentric passages including a member having' portsto alilord communication between the axial passage and tue exterior ofthe rotar)T element7 a iiexible diaphragm secured to the member, aspring pressed means to exert pressure` against the diaphragm tomaintain the member in contact with. the rotary element to clef-fe theeccentric passages.

(i. An autostop governor comprising a rotary clement having` a diametralrecess with a` piston chamber and clearance space at the bottom thereof,an eccentricallyr weighted trip element within the recess and having apiston {ittingg vithin -the piston chamber, ,adjusting means cooperatingwith the trip element to secure trippinc' at a predetermined speed, saidrotary element having axial and eccentric passages communicating withthe yclearance space, a ring adapted to close the eccentric passages andhaving one or more ports to afford communication between the axialpassage and the exterior' of the ring, manual means to withdraw the ringfrom closing position, and spring means to maintain the ring in theclosing position.

7. An auto-stop governor comprising` a rotary element. adapted to beimmersed in a liquid having' a diametral recess with a piston chamberand clearance space at the bottom thereof, an eccentrically weightedtrip element within the recess and having a piston fitting within thepiston chamber, adjusting means coopera-ting` with the trip element tosecure tripping` ata predetermined speed, said rotary element havingaxial and eccentric passages in communication with the clearance spacebelow the piston, means to close the eccentric passages, pressure meansto maintain the closure means in closed position, and means to move andmaintain the closure means in inoperative position.

8. An auto-stop governor comprising a rotary element adapted to beimmersed in a fluid and having a diametral recess withV a piston chamberand clearance space at the bottom thereof, and eccentrically weightedtrip element within the recess and having a piston portion fittingwithin the piston chamber, adjusting means cooperating with the tripelement to secure tripping at a predetermined speed, said rotary elementhaving axial and eccentric passages in communication with the clearancespace beneatn the piston portion, a ring to close the eccentric passagesand having passages to afford communication between the axial passageand the exterior thereof, a iexible diaphragm secured to the ring, andspring-pressed contro; means connected to the diaphragm.

9. An auto-stop governor coimorisingl a rotary element having` adiametral recess with a piston chamber and clearance space at the bottomthereof and adapted to be immersed in a liquid` an eccentricallyweighted trip element within the recess and havingl a piston portion[ittina` within the piston chamber, adjusting means cooperat ing withthe trip element to secure tripping at a predetermined speed,said'rotary element having` axial and eccentric passa-ges incommunication with the clearance space be neath the piston portion,closure means for the eccentric passages, control means flexibly`connected with the closure means`v spring means to maintain the closuremea-ns in active position, and means to position the control means tomaintain the closure means in inoperative position.

l0. An auto-stop governor comprising a rotary element having a recesswith a piston chamber and clearance space, an eccentrically Weightedtrip element within the recess and having a piston portion fittingrwithin the piston chamber, said rotary element having' eccentric andaxial passages within the end thereof and in communication with theclearance space beneath the piston portion, closure means for theeccentric passages having' ports to afford communication between theaxial passage and the exterior thereof, control means for the closuremeans flexibly connected thereto, supporting means for the controlmeans, spring means carried by the supporting means and cooperating withthe control means to maintain the closure means in active position.pin-andslot means cooperating with the control means and the supportingmeans to maintain the closure means in an ineffective position.

11. An auto-stop governor comprising a rotary element having a recesswith a piston chamber and clearance space at the bottom thereof andadapted to be immersed in a liquid, an eccentrically weighted trip element within the recess and having a piston portion fitted within thepiston chamber, adjustin means cooperating with the trip element tosecure tripping at a predetermined speed, said rotary element havingeccentric and axial passages in communication with the clearance spacebeneath the piston portion, a closure ring for the eccentric passage andhaving passages to afford communica- Y tion between the axial passageand the exterior thereof, a flexible diaphragm connected to the ring.y aspring control means connected to the diaphragm to maintain the closurering in effective position, and means cooperating with the last namedmeans to withdraw the closure means and maintain it in ineffectiveposition.

12. An auto-stop governor comprising a rotary element having a recesswith a piston chamber and clearance space at the bottomy thereof andadapted to be immersed in a liquid,A a casing element for the rotaryelement, an eccentrically weighted trip element within the recess andhaving a piston portion fitting the piston chamber, adjusting meanscooperating with the trip element to secure tripping at a predeterminedspeed, axial and eccentric passages in communication with one end of therota-ry element and with the clearance space beneath the piston portion,a closure ring tor the eccentric pasa: ges and haring passages adaptedto afford communication between the axial passage and the exteriorthereof, a flexible diaphragm connected to the ring, a rod Connected tothe diaphragm and passing through the easing' element, means acting onthe rod to maintain the ringjr in closingr position, and meansassociated with the rod whereby it may be withdrawn and retained in sucha position as to maintain the closure ring' ineffective.

13. in auto-stop governor comprising` a rotary element having a recesswith a piston chamber and clearance space at the bottom thereot andadapted to be immersed in a liquid, a easing,- element therefor, aneccentrically weighted trip element within the recess andY havinp` apiston portion iitting,` within the piston chamber, adjustingmeanscooperating;` with the trip element to secure trippingl at apredetermined speed, said rotary element having` axial and eccentricpassages affording eonnnunication between one end thereof and theclearance spare beneath the piston portion, a closure ring for theeccentric passages and having` passages adapted to afford communicationbetween the axial passages and the exterior thereof, a control rodflexibly connected to the closure ring, and passing;` through theeasingl element to be operative from the outside, an abutment on therod, a spring` between the abutment and a portion of said easing elementto exert pressure on the rod to cause the closure rintgto be maintainedin closing position, means `for retraetingv the rod and meanscooperating` with the rod and the springl to maintain the rod inretracted position when the latter is withdrawn and turned.

la. The combination with an auto-stop governor having an eeeentricallyweighed tripping; member and means for resisting movement of thetritugal force, of means adapted to develop centrifugal :torce of fluidpressure and adapted to be normally ineffective, and biased meansadapted to be manually operated to render said means effective.

ln testimony whereof, have hereunto subscribed my naine this 4th day otJune, 1920,

VRREN B. FLANDERS.

latter in response to een-y

